<template>
    <view>
        <view class="search-box">
          <my-search @click="gotoSearch"></my-search>
        </view>
        <view class="scroll-view-container">
            <!-- 左侧的滚动视图区域 -->
            <scroll-view class="left-scroll-view" scroll-y :style="{ height: wh + 'px' }">
                <block v-for="(item, i) in cateList" :key="i">
                    <view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">{{ item.cat_name }}</view>
                </block>
            </scroll-view>
            <!-- 右侧的滚动视图区域 -->
            <scroll-view class="right-scroll-view" scroll-y :style="{ height: wh + 'px' }" :scroll-top="scrollTop">
                <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
                    <view class="cate-lv2-title">/ {{ item2.cat_name }} /</view>
                    <view class="cate-lv3-list">
                        <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                            <image :src="item3.cat_icon"></image>
                            <text>{{ item3.cat_name }}</text>
                        </view>
                    </view>
                </view>
            </scroll-view>
        </view>
    </view>
</template>

<script>
import badgeMix from '@/mixins/tabbar-badge.js'
export default {
    data() {
        return {
            // 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
            wh: 0,
            //左侧索引
            active: 0,
            //一级分类数据
            cateList: [],
            //二级分类数据
            cateLevel2: [],
            // 滚动条距离顶部的距离
            scrollTop: 0
        };
    },
    onLoad() {
        // 获取当前系统的信息
        const sysInfo = uni.getSystemInfoSync();
        // 为 wh 窗口可用高度动态赋值
        (this.wh = sysInfo.windowHeight), this.getCateList();
    },
    methods: {
        async getCateList() {
            const res = await uni.$http.get('/categories');
            if (res.data.meta.status !== 200) return uni.$showMsg();
            this.cateList = res.data.message;
            this.cateLevel2 = res.data.message[0].children;
        },
        activeChanged(flag) {
            this.active = flag;
            this.cateLevel2 = this.cateList[flag].children;
            this.scrollTop = this.scrollTop === 0 ? 1 : 0;
        },
        gotoGoodsList(obj) {
            console.log(obj);
            uni.navigateTo({
                url: `/subpkg/goods_list/goods_list?cid=${obj.cat_id}`
                // url:"/subpkg/goods_list/goods_list?cid="+obj.cat_id
            });
        },
        gotoSearch(){
            uni.navigateTo({
                url:'/subpkg/search/search'
            })
        }
    },
    // 将 badgeMix 混入到当前的页面中进行使用
      mixins: [badgeMix],
};
</script>
<style scoped lang="scss">
.scroll-view-container {
    display: flex;

    .left-scroll-view {
        width: 120px;

        .left-scroll-view-item {
            line-height: 60px;
            background-color: #f7f7f7;
            text-align: center;
            font-size: 12px;

            // 激活项的样式
            &.active {
                background-color: #ffffff;
                position: relative;

                // 渲染激活项左侧的红色指示边线
                &::before {
                    content: ' ';
                    display: block;
                    width: 3px;
                    height: 30px;
                    background-color: #c00000;
                    position: absolute;
                    left: 0;
                    top: 50%;
                    transform: translateY(-50%);
                }
            }
        }
    }
}
.cate-lv2-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
}
.cate-lv3-list {
    display: flex;
    flex-wrap: wrap;

    .cate-lv3-item {
        width: 33.33%;
        margin-bottom: 10px;
        display: flex;
        flex-direction: column;
        align-items: center;

        image {
            width: 60px;
            height: 60px;
        }

        text {
            font-size: 12px;
        }
    }
}
.search-box {
  // 设置定位效果为“吸顶”
  position: sticky;
  // 吸顶的“位置”
  top: 0;
  // 提高层级，防止被轮播图覆盖
  z-index: 999;
}
</style>
